The syntheses of methyl 4,5-dihydro-2H-pyrazolo[3,4-a]carbazole-3-carboxylates (4a–e) from 1-oxo-1,2,3,4-tetrahydrocarbazoles (1a–e) using the intermediates, methyl 2-(1-oxo-2,3,4,9-tetrahydro-1H-carbazol-2-yl)-2-oxoacetates (3a–e) are discussed. The formation of the end products was characterised using spectral and analytical techniques.
BhattacharayyaP., and ChakrabortyD.P., Progress in the chemistry of organic natural products, HerzW., GrisebachH., KirbyG.W., and TammC. (eds), Springer Verlag, Wien, Vol. 52, 1987, pp. 299–371.
2.
ChakrabortyD.P., and RoyS., Progress in The Chemistry of Organic Natural Products, HerzW., GrisebachH., KirbyG. W., and TammC. (eds), Springer Verlag, Wien, Vol. 57, 1991, pp. 71–110.
3.
ChakrabortyD.P., The Alkaloids, BrossiA. (ed.), Academic Press, New York, Vol. 44, 1993, 257–282.
4.
HewlinsM.J.E., Oliveria-CamposA.M., and ShannonP.V.R., Synthesis, 1984, 289.
